Extension ladder jack



Jan. 29, 1957 J. H. BLUNDEAU 2,779,561

EXTENSION LADDER JACK Filed Feb. 18, 1954 Fig 3 7W 7 James H. B/undaauIN VEN TOR.

BY MME A norm ltd Stat Patnt i 2,779,561 EXTENSION LADDER JACK JamesBlundeau, Port Angeles, Wash. Application February 18, 1954, Serial No.411,108

I 1 Claim. c1.z 4s 2 ss This invention relates to new and usefulimprovements in ladder brackets and more specifically provides an extension ladder jack for use in conjunction with a rung ladder.

An object of this invention is to provide an extension ladder jack fordetachable support upon a rung ladder for positioning a scaffold boardhorizontally thereon.

Another object of the present invention is to provide an extensionladder jack which is simple in construction, easy to position and adjuston the ladder, versatile in utility,

well adapted for its purposes and relatively inexpensive to manufacture.

Yet another object of the present invention is to provide an extensionladder jack that is quickly and easily applied to or removed from a rungladder without interfering with the structure of the ladder.

A still further object of the present invention is to provide anextension ladder jack which may be utilized at any position on a rungtype ladder due to its adjustable features.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

Figure 1 is a side elevational view showing the extension ladder jack ofthe present invention secured to a rung type ladder in various positionson the ladder showing the versatility of the ladder jack;

Figure 2 is a perspective view of the extension ladder jack of thepresent invention;

Figure 3 is a longitudinal, vertical section taken substantially alongsection line 3-3 of Figure 2 showing the details of construction of theladder jack of the present invention;

Figure 4 is a detail section taken substantially along section line 4-4of Figure 3 showing the details of the spring for retaining thetelescopic members in adjusted position; and

Figure 5 is a detail section similar to Figure 4 showing a modified formof adjusting means for the telescopic members forming the extensionladder jack.

Referring now specifically to the drawings, it will be seen that thenumeral generally designates the extension ladder jack of the presentinvention for attachment to a conventional rung type ladder 12 invarious positions thereon when the ladder 12 is leaned against the wallof a building indicated by the numeral 14. It will be seen that theladder jack 10 may be extended, and in its extended position, it may beutilized when it is desired to be positioned over a basement well, aflower bed or the like adjacent the lower edge of the building wall 14.Further, the device may be collapsed for positioning on the ladder 12adjacent the contact point of the ladder 12 and the building wall 14.Further, the extension ladder jack 10 of the present invention isespecially useful for 2,779,561 Patented Jan -29, 1.1 957 with aU-shaped bracket 22 having one leg thereof secured, to the end of thetelescopic tubular member 18.

The U-shaped bracket 22 is generally elongated and has freeleg portionsfor positioning over the rung of a ladder 12. The remote end of theinner tubular member: 20 is provided with an eye bolt 24 having aflexible chain 26 secured thereto, and the chain 26 is provided with ahook .28 at its free end whichis, positionedover a rung, of a ladder 12in an, obvious, manner. Furthenljitgwill .be

seen that the chain may be looped over the rung and secured to itselfwhen in its contracted position if desirable.

Now referring specifically to Figures 3 and 4, it will be seen that theinner tubular member 20 is provided with a pair of diametrically opposedapertures 30 and the outer tubular member 18 is provided with two pairsof diametrically opposed openings 32 with one pair of the openings 32disposed adjacent the U-shaped bracket 22 and the other pair of openings32 disposed adjacent the open end of the tubular member 18. A U-shapedspring member 34 is positioned in the inner tubular member 20 andincludes return bent end portions 36 which are positioned in thediametrically opposed openings 30. When the openings 3% are aligned witha pair of the openings 32, the natural resiliency of the U-shaped spring34 urges the return bent portions 36 into engagement with the alignedapertures 30 and 32, thereby securing the tubular members it} and 2%) intelescopically adjusted position. The spring member 34 is constructed ofsuitable resilient Wire of any well known construction, and by urgingthe return bent portions 36 inwardly, the tubular members 18 and 20 maybe adjusted relative to each other.

Referring specifically to Figure 5, it will be seen that a fasteningbolt 38 having a wing nut 40 thereon is positioned in the alignedapertures 30 and 32 for positively securing the tubular members 18 and20 in adjusted position.

The operation of the device will be readily understood. The tubularmembers 18 and 20 are adjusted as desired, and the U-shaped bracket 22positioned over a ladder rung. The chain 26 with the hook 28 is thenpositioned over the ladder rung above the U-shaped bracket 22 with thehook 28 engaging the rung or else looping the chain 26 around the rungand engaging the hook 28 with a link of the chain 26, in an obviousmanner. With this specific structure, it will be seen that the extensionladder jack ltl is supported in a horizontal position for positioning ascaffold board 42 thereon in a horizontal position which is necessaryfor the safe use of the scaffold. Only a single ladder jack has beendescribed, and it will be understood that a pair of the ladder jacks It)will be necessary in order to support a scaffold board.

From the foregoing, the construction and operation of the device will bereadily understood and further explanation is believed to beunnecessary. However, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction shown and described, andaccordingly, all suitable modifications and equivalents may be resortedto, falling within the scope of the appended claim.

What is claimed as new is as follows:

A ladder jack for supporting a horizontally disposed the outer end ofthe outer tubular member, said U-shaped bracket having one leg securedto and forming a closure for the outer tubular member, said U-shapedbracket opening downwardly for receiving a ladder rung therebysupporting one end of the jack, the outer end of the inner member havinga flexible chain terminally attached thereto, a hook on the free end ofthe chain whereby the free end of the chain may be looped around aladder rung above the U-shaped bracket and the hook engaged with a linkof the chain thereby supporting the other end of the jack, said tubularmembers having spaced pairs of alignable apertures, a U-shaped springdisposed in said inner tubular member, said spring having legs extendinglongitudinally in said inner member and each terminating in an outwardlyextending U-shaped projection having a rounded bight portion forextending through aligned apertures for retaining the tubular members inlongitudinally adjusted position, said hook permitting adjustment in thelength of the chain for disposing the tubular members in horizontalposition for supporting a scaffold board thereon with the adjustment ofthe tubular mem bers permitting the board to be adjusted inwardly oroutwardly in relation to a ladder.

References Cited in the file of this patent UNITED STATES PATENTS791,531 Althoif June 6, 1905 1,452,182 Butrum Apr. 17, 1923 1,576,695Weber Mar. 16, 1926 2,229,475 Redmer Jan. 21, 1941 2,488,480 Spirt Nov.15, 1949 2,488,984 Pennington Nov. 22, 1949 2,548,380 Patham Apr. 10,1951 2,577,286 Streeter Dec. 4, 1951 2,578,119 Yench Dec. 11, 1951FOREIGN PATENTS 798,851 France Mar. 11, 1936

